content: /* ===========================================================
   * JFreeChart : a free chart library for the Java(tm) platform
   * ===========================================================
   *
   * (C) Copyright 2000-2013, by Object Refinery Limited and Contributors.
   *
   * Project Info:  http://www.jfree.org/jfreechart/index.html
   *
   * This library is free software; you can redistribute it and/or modify it
   * under the terms of the GNU Lesser General Public License as published by
   * the Free Software Foundation; either version 2.1 of the License, or
   * (at your option) any later version.
   *
   * This library is distributed in the hope that it will be useful, but
   * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
   * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
   * License for more details.
   *
   * You should have received a copy of the GNU Lesser General Public
   * License along with this library; if not, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
   * USA.
   *
   * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
   * Other names may be trademarks of their respective owners.]
   *
   * ---------------------
   * ObjectUtilitiess.java
   * ---------------------
   * (C) Copyright 2003-2013, by Object Refinery Limited.
   *
   * Original Author:  David Gilbert (for Object Refinery Limited);
   * Contributor(s):   -;
   *
   * Changes
   * -------
   * 25-Mar-2003 : Version 1 (DG);
   * 15-Sep-2003 : Fixed bug in clone(List) method (DG);
   * 25-Nov-2004 : Modified clone(Object) method to fail with objects that
   *               cannot be cloned, added new deepClone(Collection) method.
   *               Renamed ObjectUtils --> ObjectUtilities (DG);
   * 11-Jan-2005 : Removed deprecated code in preparation for 1.0.0 release (DG);
   * 18-Aug-2005 : Added casts to suppress compiler warnings, as suggested in
   *               patch 1260622 (DG);
   * 16-Jun-2012 : Moved from JCommon to JFreeChart (DG);
   *
   */
  
  package org.jfree.chart.util;
  
  import java.lang.reflect.InvocationTargetException;
  import java.lang.reflect.Method;
  import java.lang.reflect.Modifier;
  import java.util.Collection;
  
  /**
   * A collection of useful static utility methods for handling classes and object
   * instantiation.
   */
  public final class ObjectUtilities {
  
      /**
       * Default constructor - private.
       */
      private ObjectUtilities() {
      }
  
      /**
       * Returns <code>true</code> if the two objects are equal OR both
       * <code>null</code>.
       *
       * @param o1 object 1 (<code>null</code> permitted).
       * @param o2 object 2 (<code>null</code> permitted).
       * @return <code>true</code> or <code>false</code>.
       */
      public static boolean equal(final Object o1, final Object o2) {
          if (o1 == o2) {
              return true;
          }
          if (o1 != null) {
              return o1.equals(o2);
          }
          else {
              return false;
          }
      }
  
      /**
       * Returns a hash code for an object, or zero if the object is
       * <code>null</code>.
       *
       * @param object the object (<code>null</code> permitted).
       * @return The object's hash code (or zero if the object is
       *         <code>null</code>).
       */
      public static int hashCode(final Object object) {
          int result = 0;
          if (object != null) {
              result = object.hashCode();
          }
          return result;
      }
  
      /**
       * Returns a clone of the specified object, if it can be cloned, otherwise
       * throws a CloneNotSupportedException.
       *
       * @param object the object to clone (<code>null</code> not permitted).
       * @return A clone of the specified object.
       * @throws CloneNotSupportedException if the object cannot be cloned.
       */
      public static <T> T clone(final T object)
          throws CloneNotSupportedException {
          if (object == null) {
              throw new IllegalArgumentException("Null 'object' argument.");
          }
          if (object instanceof PublicCloneable) {
              final PublicCloneable pc = (PublicCloneable) object;
              return (T) pc.clone();
          }
          else {
              try {
                  final Method method = object.getClass().getMethod("clone");
                  if (Modifier.isPublic(method.getModifiers())) {
                      return (T) method.invoke(object);
                  }
              }
              catch (NoSuchMethodException e) {
                  //Log.warn("Object without clone() method is impossible.");
              }
              catch (IllegalAccessException e) {
                  //Log.warn("Object.clone(): unable to call method.");
              }
              catch (InvocationTargetException e) {
                  //Log.warn("Object without clone() method is impossible.");
              }
          }
          throw new CloneNotSupportedException("Failed to clone.");
      }
  
      /**
       * Returns a new collection containing clones of all the items in the
       * specified collection.
       *
       * @param collection the collection (<code>null</code> not permitted).
       * @return A new collection containing clones of all the items in the
       *         specified collection.
       * @throws CloneNotSupportedException if any of the items in the collection
       *                                    cannot be cloned.
       */
      public static <T, C extends Collection<T>> C deepClone(final C collection)
          throws CloneNotSupportedException {
  
          if (collection == null) {
              throw new IllegalArgumentException("Null 'collection' argument.");
          }
          // all JDK-Collections are cloneable ...
          // and if the collection is not clonable, then we should throw
          // a CloneNotSupportedException anyway ...
          final C result = ObjectUtilities.clone(collection);
          result.clear();
          for (T item : collection) {
              if (item == null) {
                  result.add(null);
              } else {
                  result.add(clone(item));
              }
          }
          return result;
      }
  
  }
  